1. Field of the Invention
The present invention relates to a structure of shockproof spindle, and more particularly to a structure that has a C-shaped washer, which has an opening to enable a new assembly process of the structure of spindle. Because of the new assembly process, the structure can be modified to prevent falling of a ball guided in the structure under impact. In addition, the thickness of the washer can be increased also, and that can improve the impact absorbing efficiency of the structure.
2. Description of Related Art
A conventional structure of shockproof spindle is installed in an electric tool, such as an electric drill, for drilling cement wall, and has impact absorbing function. The structure absorbs the impact when a tool installed on the end of the spindle is shocked against the workpiece during the operation of the tool. Since the structure works smoothly, the damage or destruction of assembly precision, made by the impact, of the parts in the electric tool is avoided, and the structure is more compact and the operation period is increased.
Referring to FIG. 1, in a conventional structure of shockproof spindle, a spindle 1 is inserted through a washer 2, an elastomer 3, and a sleeve 4 sequentially. The sleeve 4 caps the elastomer 3 while the elastomer 3 presses on the top of a base 11 fixed at the bottom end of the spindle 1. Next, a ball 5 is positioned in a chute 41 defined in the sleeve 4, while the sleeve 4 is pushed down to compress the elastomer 3 until the ball 5 can be retained in a chute 12 of the spindle 1 tightly.
In addition to all of the above, the elastomer 3 held between the base 11 and the sleeve 4 absorbs impact energy when a tool installed on the end of the spindle 1 is shocked against the workpiece during the operation of the tool. Since the spindle 1 works smoothly owing to the effect of the elastomer 3, the operators work more easily, and the damage or destruction of assembly precision, made by the impact, of the parts in the electric tool is avoided.
Furthermore, because the ball 5 of the conventional structure of shockproof spindle can only be installed in the chute 41 of the sleeve 4 after all the other part assembly is finished, the elastomer 3 has to be short enough for the chute 41 of the sleeve 4 to be lower than the chute 12 for the installation of the ball 5. However, such a design of the elastomer 3 or the chute 41 of the sleeve 4 leads to the problems that the chute 41 is lower than the chute 12 of the spindle 1 under impact, and the ball 5 may fall out from the chute 12. These problems not only cause the spindle to lose function of impact absorbing but also destroy the transmission mechanism.
To overcome the shortcomings, the present invention provides a structure of shockproof spindle to mitigate the aforementioned problems.